A tuber is a part of a plant that is its modified organ. It is necessary for the body to perform additional functions. Features of its structure and varieties of tubers of various origins will be discussed in detail in this article.
The purpose of the modifications
Underground and aboveground organs of plants are, respectively, the root and shoot. These vegetative parts serve for air and soil nutrition, as well as for asexual reproduction. But in certain conditions, additional functions are needed for the process of adaptation and increase in viability. For these purposes, modifications are needed. The tuber is a prime example of one of them.
Root crops are a good example of the modification of the underground organ of plants. They are formed in carrots, beets, radishes, radishes. This is a thickening of the main root, in which water and nutrients are stored. Man uses them for food and as forage crops.
Escape Modifications
Tuber and rhizome are modifications of above-ground organs. There is nothing surprising in this. Despite the locationunderground, in their structure they have all the parts of the escape. Their examples are tubers, bulbs, rhizomes, tendrils and whiskers. Each of them has its own structural features that determine their functions. For example, strawberry tendrils are essential for vegetative propagation of this plant. Despite the fact that it forms flowers and seeds, this method is the most essential. But the grape mustache is needed to attach its lashes to the support.
A leek or garlic bulb consists of a flat stem called the bottom. Adventitious roots are attached to it. They grow in bunches. This is a typical structure for a fibrous root system. There are also buds and several types of leaves on the bottom. Some of them are juicy and meaty. They store water and nutrients. Others are dry and dense, serving as additional protection against mechanical damage and excessive transpiration. From the buds located on the bottom, young green leaves periodically grow. They are called green onions. All of the above structural features prove once again that the bulb is a modification of the shoot.
Structure of a tuber
The next example of the modification of above-ground organs is a tuber. It is typical for potatoes, Jerusalem artichoke, kohlrabi. The tuber is the result of thickening of the internodes of the stem, which can be both sub- and above-ground.
Its base is a thick stem, rich in starch and other substances. The bark protects it from adverse environmental conditions. Exactlywe clean it when we use potatoes for cooking. There are also kidneys on the thickened stem tuber of the potato. They are called eyes. With their help, vegetative propagation of this plant is carried out. In the spring, young shoots appear from the buds, which form a bush and new tubers.
Root tuber
Not only shoots can form tubers. The underground part of the plant is also no exception. So, the root tuber is characteristic of dahlia, sweet potato and chistyak. It is nothing more than a thickening of the adnexal components of the fibrous root system. Despite the different origin and location, such modifications perform exactly the same functions.
Functions
The main purpose of both stem and root tubers is to store water with nutrient mineral and organic substances dissolved in it. Everyone knows how rich in starch potatoes are. It is in its tubers, in the cells of the storage basic tissue, that plastids, leukoplasts, containing carbohydrates are located. In this form, plants with these changes easily endure adverse conditions, surviving them underground.
Another important function of this modification is the implementation of vegetative reproduction. To grow potatoes, it is enough to cut the tuber into several parts, each of which must have buds - eyes, and plant them in the ground. This plant has fruits capable of producing seeds. But their number is small. Since the potato hasimportant economic importance, scientists-breeders have attempted to develop new varieties with a large number of seeds. But the vegetative method of reproduction with the help of tubers turned out to be more productive.
Because the tuber is a storehouse of nutrients, these modified elements are used as food. And Jerusalem artichoke is able to lower the level of glucose in the blood with constant use. Doctors recommend it to people suffering from diabetes. Eating potatoes provides the body not only with the necessary daily carbohydrate content, but also with valuable microelements, such as phosphorus and potassium.
Thus, tubers are modifications of the shoot or root and serve to store nutrients, vegetative propagation. They are of great food and economic importance.
